Rotary compressor, pump or the like



R. SCHMIDT as, s, 1931.

ROTARY COMPRESSOR, PUMP, OR THE LIKE Filed March 8, 1929 2 Sheets-Sheetl WWW/III Be s, 1931. SCHMIDT 1,834,976

ROTARY COMPRESSOR, PUMP, OR THE LIKE Filed March 8, 1929 2 Sheets-Sheet2 bearings.

Patented Dec. 8, 1931 UNITED STATES PATENT OFFICE RUDOLF SCHMIDT, OFVIENNA, AUSTRIA, ASSIGNOR TO PATIAG PATENTVERWER- TUNGS-UND INDUSTRIEAKTIENGESEILSCHAFT, OF VADUZ, LIECHTENSTEIN, A

CORPORATION OF LIECHTENSTEIN ROTARY COMPRESSOR, PUMP OR THE LIKEApplication filed March 8, 1929, Serial No. 345,455, and in AustriaMarch 9, 1928.

This invention relates to an improved rotary compressor, pump or thelike. According to the'invention the rotary compressor comprises incombination a cylindric casing, two cam-shaped pistons having a contourline free from recesses, rolling on each other with a slight clearance,gear wheels operating the said pistons and constituting a geared pump, apipe leading from the pressure side of the geared pump to a nozzle forcontinually pressing sealing liquid against the clearance between thetwo pistons.

One mode of carrying out the present in- 'vention is illustrated by wayof example on the accompanying sheets of drawings in which- Fig. 1 showsan embodiment in sectional elevation.

Figs. 2 and 3 are cross-sectional views, the sections being taken online 22 and on line 3-3 of Fig. 1 respectively.

Fig. 4 is a diagrammatic view of the plant.

1 designates the casing of the compressor (pump), 2 is the shaft of thetop piston 5, 3 and 4 are ball hearings in which the said shaft runs, 6designates the shaft of the bottom piston 9 and 7, 8 the correspondingball A shaft 10 operates the piston 9 by means of gear Wheels 11 and 12.The shaft 2 and the top piston 5 are operated by the piston 9 by meansof toothed wheels 14, 15, arranged in a gear case 13 and operating asrotary gear pump for the objects hereinafter set forth. S designates thesuction channel and D the delivery (pressure) channel of the encasedgear.

The rotary gear pump sucks-in oil, supplied by an oil separator A (Figs.2 and 4), through the pipe 16 and delivers the same by way of a pipe 17to a'nozzle 18, which continuously ejects towards the approaching zoneof the two pistons 5 and 9 the oil at a pressure somewhat higher thanthe delivery pressure of the compressor (pump). In this way a steady andsealing oil flow is maintained in the zone of the nearest approach ofboth cam-shaped pistons as Well as in the packing zone between the bodyof piston and the casing.

Besides the branch current just described,

by way of the nozzle 18 and the bores 22, 23

through the packing faces, is separated from the supplied air in theseparator A (into which both are delivered by way of the pipe 24) and isagain delivered to the geared pump by way of the pipe 16.

The pumps or compressors constructed according to the present inventiondo not require to be lubricated in usual manner because directlycontacting faces are not present between the moving delivery members andthe casing. Instead of a direct contact, the moving surfaces approacheach other and the walls of the casing, the extent of approach dependingon the size of the compressor or pump. Thereby, in case of compressors,the quantity of delivered sealing liquid'amounts only to a fraction ofthe quantity of air or gas which would flow through the same packingfaces at the same conditions of pressure. Therefore the total volumetricefl iciency of the delivered medium (which consists of a mixture of airor gas and the sealing liquid) of a compressor constructed according tothe present invention is considerably higher than would be the case ifair or gas alone is delivered.

I claim 1. In a rotary compressor, pump or the like a cylindric casing,two cam-shaped pistons having a contour line free from recesses, rollingon each other with a slight clearance, gear wheels operating the saidpistons and constituting a geared pump, a pipe leading from the pressureside of the geared pump, and a nozzle connected with said pipe anddirected toward the clearance between the two pistons for continuallypressing sealing liquid against said clearance between the two pistons.

2-. In a rotary compressor, pump or the like a cylindric casing, twocam-shaped 'pistons having a contour line free from recesses, rolling oneach other with a slight clearance, gear wheels operating the saidpistons and constituting a geared pump, a pipe leading from the pressureside of the geared pump, a nozzle connected with said pipe and directedtoward the clearance between the two pistons for continually pressingsealing liquid against said clearance, axial bores inthe shafts of thepistons communicating with the pressure side of the geared pump andtransverse bores to the said axial bores leading to the clearancesbetween the side facesof the casing and the side faces of the pistons,so that sealing liquid is continually pressed in the last mentionedclearances.

RUDOLF SCHMIDT.

